The invention relates to a device and a method for measuring the size and the movement speed of bubbles in a concentrated phase gas-solid fluidized bed, belonging to devices and methods for measuring movement behaviors of bubbles. The device comprises a gas-solid fluidized bed, a diffuser chamber, an airflow distributing plate, a high-speed dynamic camera, a data signal display and a data acquisition output and storage device. A high-density magnetite powder medium solid is stood in a gas-solid fluidized bed body, compressed air is diffused to generate uniform and stable bubble flows in the fluidized bed, the high-speed dynamic camera arranged on the front part of the fluidized bed is regulated to capture movement images of the bubbles penetrating through some bed plane, image information is immediately displayed on the data signal display and is continuously transmitted to the data acquisition output and storage device, and then effective data of the size and the movement speed of the bubbles can be obtained after accurate calculation. The device and method have the advantages of simple structure, convenience for operation, easy control, high measurement precision, good reliability, capability of realizing accurate measurement and accurate prediction of the single bubbles in a stable gas-solid multi-phase flow, and wide application range.

Device and method for measuring size and movement speed of bubbles in concentrated phase gas-solid fluidized bed

The present disclosure provides a cooling system of an emergency cooling tank, which enables long-term cooling without refilling cooling water, in case of the change in a quantity of heat transferred to the emergency cooling tank according to a lapse of time upon an occurrence of an accident of a nuclear reactor, and a nuclear power plant having the same. The emergency cooling tank cooling system includes an emergency cooling tank configured to store cooling water therein, the cooling water receiving heat, transferred from a nuclear reactor or a containment, when an accident occurs in the nuclear reactor, a heat exchanging device installed to be exposed to an outside of the emergency cooling tank to operate in air, and configured to externally emit heat by way of a heat exchange between fluid in the emergency cooling tank and the air such that the operation of the emergency cooling tank is continued even without refilling the cooling water, and an opening and closing unit installed at an upper portion of the emergency cooling tank to be located higher than a water level of the cooling water, and configured to be open by a flow of the fluid generated by an evaporation of the cooling water, the flow being formed due to a pressure difference from external air at pressure higher than a preset pressure, such that some of the fluid is externally emitted when a heat load exceeding a cooling capacity of the emergency cooling tank is transferred.

Cooling system of emergency cooling tank and nuclear power plant having the same

Hydrogen bubble flow display technology-based boundary layer visual test device

The invention provides a two-phase flow device for researching the enhancement of the natural circulation capacity of a system. The two-phase flow device consists of a circulating water system, an air bubble generation device, an air supply system and a data acquisition system, wherein the circulating water system mainly comprises an open type water tank, a filter device, a heat exchanger and other relevant pipelines and valves; the air bubble generation device is a core of the device and consists of an external sleeve and a multiporous medium sleeve; the air supply system mainly comprises an air compressor, an air storage tank and a pressure reducing valve; the data acquisition system mainly consists of an integrated data acquisition system, a high-speed camera system, a gas mass flow meter, an electromagnetic flow meter, a pressure sensor and a temperature sensor. The two-phase flow device can effectively solve the problem of disturbance to a natural circulation system due to active air injection and reduce the additional resistance involved into a circulation loop; the device is simple, easy to operate and uniform in foaming; stable bubble flow can be obtained; the two-phase flow device is favorable for scientific design of natural circulation and two-phase flow and engineering design of a passive safety system.

Two-phase flow device for researching enhancement of natural circulation capacity of system

Bubble parameter measurement method and device

Condensation heat-transfer experiment device capable of realizing coupling of natural circulation and forced circulation

The invention provides a self-support type heat exchanger with mixed arrangement of pin-fin tubes and bare tubes, which comprises a shell, a tube bundle disposed inside the shell, wherein the two ends of the tube bundle are respectively disposed on a fixed tube plate and a floating tube plate, the fixed tube plate is fixedly installed between the lower end of the shell and a channel, an upper header is disposed at the upper end of the shell, a shell pass inlet port and a shell pass outlet port are disposed on the shell, a tube pass inlet port and a tube pass outlet port are disposed on the channel, and the tube bundle is composed of bare tubes and pin-fin tubes with high-efficient heat transfer capability in a mixed arrangement. The invention provides a self-support type heat exchanger with mixed arrangement of pin-fin tubes and bare tubes. The inventive heat exchanger has no need of baffles and tube supporting elements; and mixes the pin-fin tubes and the bare tubes together, so that the pin-fins of the pin-fin tubes form mutual support with the bare tubes, thereby achieving the purposes of reducing tube vibration, reducing heat exchanger volume, and improving unit volume heat exchange efficiency of the heat exchanger.

Needle fin tube and plain tube mixedly arranged self-supporting type heat exchanger

The utility model provides a non-dynamic safety case cooling system comprising a pool, an internal vaporizer pipe truss, a vapor-water separator and an external air cooling device. The pool is arranged in a ring-shaped cavity combined by an inner layer concrete safety case and an outer layer concrete safety case. The external air cooling device is arranged between the domes of the inner layer concrete safety case and the outer layer concrete safety case. An internal vaporizer and the vapor-water separator are arranged in the inner layer concrete safety case. Two ends of the internal vaporizer are respectively connected with the vapor-water separator through two pipes. The vapor-water separator is connected with the external air cooling device through a first pipe extending out of the inner layer concrete safety case. The internal vaporizer pipe truss is communicated with the pool through a second pipe extending out of the inner layer concrete safety case. When accidents such as loss of coolant accident (LOCA) and main steam line burst (MSLB) happen, the non-dynamic safety case cooling system can safely and reliably conduct out heat in the safety case for a long term, ensures that the temperature and pressure in the safety case do not surpass designed limit values, and ensures integrity of the safety case.

Non-dynamic safety case cooling system

The invention aims to provide a passive residual heat exhausting system for a molten salt reactor. The passive residual heat exhausting system comprises a salt discharging pot, heat exchanging elements, a steam pocket and a ventilator, wherein the upper part of each heat exchanging element is located in the steam pocket, the lower part of each heat exchanging element is located in the salt discharging pot, and other parts of each heat exchanging element are located between the steam pocket and the salt discharging pot; each heat exchanging element comprises a heat transferring pipe; each heat transferring pipe is internally provided with a middle sleeve; each middle sleeve comprises an inner wall and an outer wall; a channel for steam to flow through is formed between each inner wall and the corresponding outer wall; a water inlet pipeline is formed in the inner wall of each middle sleeve, a water inlet is formed in the top of each water inlet pipeline, and the bottom end of each water inlet pipeline is disconnected and is communicated with the corresponding channel; the ventilator is internally provided with an air cooler; an air cooler inlet is formed in the end part of the air cooler and a fin pipe is arranged in the middle of the air cooler; the steam pocket is communicated with the air cooler inlet. According to the passive residual heat exhausting system for the molten salt reactor provided by the invention, the passive working capability of the system is improved, the problems of high fault rate and the like caused by the design of an active system are solved, and therefore, the safety of the residual heat exhausting system for the molten salt reactor is improved.

Passive residual heat exhausting system for molten salt reactor

The invention aims at providing a two-phase flow interface parameter distribution characteristic experiment device under swinging condition, which comprises a water storage box, a mixing chamber, an experiment section, an air-water separation device, an air compressor, an air storage tank, a swing table, photoelectric converter and a light source, wherein the mixing chamber and the steam-water separation device are respectively installed at both ends of the experiment section, the water storage box is connected with the air-water separation device and the mixing chamber respectively, the air storage tank and the air compressor are connected in parallel and connected with the mixing chamber, and the mixing chamber is also connected with the swing table; and an optical fiber probe and a pressure sensor are installed on the experiment section, the photoelectric converter faces to the optical fiber probe, and the light source faces to the photoelectric converter. The invention further develops and perfects an experiment device for researching the air-liquid two-phase local parameter distribution and transportation mechanism in a large channel under the steady-state condition, foaming is uniform in the experiment, a stable bubble flow can be obtained, and the outlet pressure of the air-water separation device maintains constant by means of gravity separation.

Cao Xiaxin

Papers

Condensation heat-transfer experiment device capable of realizing coupling of natural circulation and forced circulation

Needle fin tube and plain tube mixedly arranged self-supporting type heat exchanger

Non-dynamic safety case cooling system

Passive residual heat exhausting system for molten salt reactor

Two-phase flow interface parameter distribution characteristic experiment device under swinging condition